I grew up in New Jersey, often stereotyped as the land of big hair and long nails. I have been getting regular manicures and pedicures for as long as I can remember without ever worrying about the potential hazards of these little indulgences. That is, until a friend recently proved those urban legends true by contracting a nasty fungal infection after having her toes painted — and at a high-end spa, to boot!

"In general, today's nail cosmetics and nail salons are quite safe," says New York dermatologist Richard Scher, a professor emeritus at Columbia University. "However, there is a small risk of adverse effects that are not incredibly common but are something that people should be aware of."

To start, he cites the potential for allergic reactions to chemicals, including formaldehyde and acetone, that are found in some nail products. And you can't always trust labels: Last month, the California Department of Toxic Substances Control released a small study showing that several "toxic free" polishes actually contained one or more chemicals that have been linked to cancer and birth defects.

Scher also urges caution with gel manicures, which are cured under a UV light and removed with acetone. In addition to possible skin damage to hands from repeated exposure to the UV lights that cure the polish, Scher warns that acetone can cause itching, dryness and flaking or peeling skin.

Washington dermatologist Ella Tombs contends that these treatments use only small amounts of UV light for short periods and don't pose a real health risk. She worries more about technicians who scrub too vigorously underneath your nails or push back cuticles too far, both of which can cause injury and allow bacterial or fungal infection.

"You don't want people to cut or clip your cuticles at all, since it can traumatize and damage them and open you up to an infection," she adds, noting that cuticles serve as a skin barrier to germs.

What precautions should someone getting a manicure or pedicure take before heading off to the salon? First and foremost, it's important to bring your own instruments - such as clippers, nail files and pumice stones - to avoid picking up germs from another client, says Washington podiatrist Erika Schwartz: "If salon employees are just dipping their instruments in some kind of solution, that's not going to kill bacteria and fungus," she advises. "They should be using an autoclave, a type of machine for sterilizing instruments."

With flip-flop season under way, the American Podiatric Medical Association offers these additional tips regarding pedicures:

• Schedule your appointment first thing in the morning, when foot baths are typically cleanest. If you're not a morning person, make sure that the salon filters and cleans the foot bath between clients using bleach and other disinfectants.

• Resist the urge to shave your legs before receiving a pedicure. Freshly shaven legs or small cuts on your legs may allow bacteria to enter.

• While it's okay to use a pumice stone, foot file or exfoliating scrub to remove calluses or dead skin on your feet, avoid foot razors. These tools can do permanent damage if used incorrectly and easily cause infection if too much skin is removed.

• Don't round the edges of your toenails. This type of shape increases the chances that painful ingrown toenails will develop.

• Finally, it can be worthwhile to give your nails a break from the latest and greatest shade of polish every now and again — this is especially so for the toes.

"People like to have pedicures done straight through the summer or even all year long, but the problem with that is nails don't get an opportunity to breathe," says Washington podiatrist Howard Osterman, who notes that chemicals in nail polish can eat away at the top layer of toenails, resulting in changes in color or texture that may or may not be a sign of a true medical issue. "Fungus grows in dark, moist environments, so anything that doesn't let air dry it out – such as nail polish – can allow fungus to (grow) underneath," he explains, noting that clear nail polish isn't any better than colored, since it's the enamel itself that's the problem.

Osterman points out that pretty hues can also mask infections, skin cancer and other medical problems, and he suggests at the very least changing your polish frequently, so you can keep a close eye on the state of your nails.